Confused by CLAP_EVENT_NOTE_EXPRESSION (e.g. Pitchbend)

[sagantech]

So I am wondering the preferred method of a host to translate straight MIDI events (say from a standard MIDI controller) to CLAP_NOTE_DIALECT_CLAP. I am most concerned about the bend wheel and the modulation wheel. I notice that some plug-ins respond to CLAP_NOTE_EXPRESSION_TUNING for pitch bending but I assume that is not the preferred method. Also it does not look like many plug-ins respond to CLAP_NOTE_EXPRESSION_VIBRATO if I send that for modulation (controller 1).

Any help greatly appreciated.

[robbert-vdh]

If a plugin supports it, CLAP_NOTE_EXPRESSION_TUNING is the preferred method for pitch expressions since it has a defined range of -120 to +120 semitones. In contrast, MIDI pitch bends are untyped. That also means you cannot translate MIDI pitch bend into tuning expressions without defining the a pitch bend range first. If they're MIDI pitch bends and the plugin supports MIDI events, you should just pass them through as is using CLAP_EVENT_MIDI.

[sagantech]

Thanks for the quick reply.
Some plug-ins do not support CLAP_EVENT_MIDI. My host does know what range of pitch bend the user desires.
What about modulation?

[robbert-vdh]

You can translate the pitch bend to note expressions then. I'd just add a per-plugin toggle somewhere to let the user choose between MIDI messages and CLAP note expressions if the plugin supports both note event formats.

[sagantech]

translate the pitch bend to note expressions

Do you mean by using CLAP_NOTE_EXPRESSION_TUNING or is there some other way?

[robbert-vdh]

Yes, CLAP_NOTE_EXPRESSION_TUNING.

[sagantech]

I already have a way to select the MIDI dialect per plug-in. Here are the explicit issues I am facing and admittedly they are minor:

1. Apricot does not respond to modulation wheel (CLAP_NOTE_EXPRESSION_VIBRATO ) and does not support CLAP_EVENT_MIDI. Works fine with CLAP_NOTE_EXPRESSION_TUNING
2. The just released HIVE works fine with CLAP_EVENT_MIDI but in CLAP_NOTE_DIALECT_CLAP does not respond to CLAP_NOTE_EXPRESSION_TUNING or CLAP_NOTE_EXPRESSION_VIBRATO. The GUI pitch bend wheel works fine in this dialect.